1. Technical Field
The present disclosure is directed to tissue sampling devices and, more particularly, to tissue sampling devices including sensory feedback elements and methods of using the same.
2. Discussion of Related Art
In general, sampling devices, e.g., pipettes, syringes, etc., consist of a cylindrical barrel having a distal end adapted to permit passage of biological materials therethrough and a proximal end adapted to receive a stopper and plunger rod assembly. The stopper functions to provide a fluid tight seal between itself and the barrel so that movement of the stopper along the barrel will cause the biological material to be drawn into or forced out of the barrel through the distal end. The stopper is moved along the barrel by applying axial force to the plunger rod which is connected to the stopper. The plunger rod is sufficiently long to be accessible outside of the barrel. Typically, indicia, such as volume measuring indicia, are provided along the length of the barrel to indicate to the user the volume of the biological material contained within the barrel.
The material drawn into or forced out of the sampling device can consist of biological fluids, e.g., blood, plasma, serum, urine, cerebrospinal fluid, etc., or solids, e.g., organs, tissue fragments, etc., which are not distributed in a systematically homogeneous manner in the sampling device as compared to biological fluid. In instances where biological solids are involved, the collection and sampling process becomes more complex and the devices often have to be adapted to each particular case according to the greater of lesser fluidity or viscosity of the biological solids.
Analysis of biological solids is currently performed in the diagnosis of a number of diseases, such as, for example, the diagnosis of transmissible spongiform encephalopathies (TSE), which are degenerative neurological diseases, e.g., scrapie in sheep, “mad cow disease”, also called bovine spongiform encephalopathy (hereafter “BSE”), in cattle, Creutzfeldt-Jakob disease (CJD) and kuru in humans, and related transmissible spongiform encephalopathies.
In the case of BSE, diagnosis currently requires a biological sample to be collected from the brain matter, especially from the animal's brain stem and more particularly from the sensory and motor nuclei of the vagus nerve, which constitute the zone of preferential accumulation of PrPres (abnormal form of a protein called “prion protein”), the diagnostic marker of BSE. The sample collected is then subjected to various treatments for extraction of PrPres which is then analyzed by immunoassay. In view of its plastic properties and its viscosity, bovine brain matter is not easy to sample in a simple, rapid, reproducible, quantifiable and safe manner. For mass screenings of bovine carcasses, it is essential that the tests are affected in the simplest and quickest manner possible after slaughter and as reproducibly, quantifiably and safely as possible, i.e. with the best possible sensitivity and without external contamination.
There is, therefore, a continuing need for devices for collecting a soft biological sample, particularly brain matter, which is simple and/or quick to use, is economic, has a reproducible performance and is quantifiable, effective and safe from any external contamination. There is also a need for methods of carrying out this type of sampling.
“Soft biological sample” is to be understood as meaning a sample of a biological material whose consistency is such that it can be cut effortlessly with a tool such as a scalpel, e.g., brain matter. “Brain matter” is to be understood as meaning any portion of the mass constituting the central nervous system, and particularly, but not exclusively, the anatomical part conventionally called the “brain stem”, especially that which is centered on the sensory and motor nuclei of the vagus nerve, whether said matter be in the natural state or whether it has been treated, e.g. obtained in the form of a pasty ground material.